n = int(input())
ans = n - 1 if n > 2 else n + 1
for i in range(2, int(n ** 0.5 + 9)):
    sm = 0
    while sm <= n:
        sm = sm * i + 1
        if n % sm == 0 and n // sm < i:
            ans = min(ans, i)
    if n % i == 0 and i < n // i - 1:
        ans = min(ans, n // i - 1)
print(ans)